Integrating In-situ Two-Wavelength Pyrometry with Thermal Field Modeling to Elucidate Solidification Microstructure in LPBF of IN718

Integrating In-situ Two-Wavelength Pyrometry with Thermal Field Modeling to Elucidate Solidification Microstructure in LPBF of IN718 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Integrating In-situ Two-Wavelength Pyrometry with Thermal Field Modeling to Elucidate Solidification Microstructure in LPBF of IN718 Yuzhe Liu, Haolin Zhang, Chaitanya Vallabh, Jorg Wiezorek, Xiayun Zhao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9060187/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract This initial study combines experimentally measured melt pool surface temperatures using a novel single-camera two-wavelength imaging pyrometry (STWIP) system with COMSOL numerical simulation to investigate the relationship between thermal evolution and microstructure formation during laser powder bed fusion (LPBF) of IN718. Using the Kurz-Fisher dendritic growth model, quantitative solidification microstructure metrics, such as primary dendrite arm spacings (PDAS), are linked to local solidification interface characteristics, including thermal gradient and growth velocity. By integrating STWIP temperature measurements with post-mortem SEM imaging of solidified microstructures and constraining numerical thermal-field simulations with these experimental data, the framework enables location-specific estimation of solidification interface properties and their influence on microstructure evolution. This work presents a preliminary, experimentally grounded framework that directly leverages measured melt pool thermodynamics—rather than relying on purely simulated temperatures—to analyze the interplay between laser processing parameters, melt pool dynamics, and resulting microstructure. While demonstrated for IN718, the approach is broadly extensible to other alloys and LPBF conditions, highlighting the potential of high-acquisition-rate, emissivity-independent in-situ pyrometry to support microstructure prediction, process understanding, and data-driven parameter optimization in additive manufacturing of high-performance alloys. Additive manufacturing Inconel solidification microstructure two-wavelength pyrometry thermal field Full Text Supplementary Files GraphicalabstractOverallWorkflow.png Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 06 Apr, 2026 Reviewers invited by journal 19 Mar, 2026 Editor assigned by journal 19 Mar, 2026 First submitted to journal 17 Mar, 2026 Editorial decision: Minor Revisions Needed 15 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9060187","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":608876402,"identity":"cc32aee8-06d1-4791-b9de-a1c885bff162","order_by":0,"name":"Yuzhe Liu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yuzhe","middleName":"","lastName":"Liu","suffix":""},{"id":608876403,"identity":"5b344a8e-de73-47e8-a129-028ac0b8de87","order_by":1,"name":"Haolin 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